kernel.org has a public (read-only) git repository that you can clone. It has also tags for every kernel version, so you can checkout a specific version: # Clone the kernel to your local machine $ git clone git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable.git $ cd linux-stable # Find the tag for the version you want $ git tag -l | … Read more
request_mem_region tells the kernel that your driver is going to use this range of I/O addresses, which will prevent other drivers to make any overlapping call to the same region through request_mem_region. This mechanism does not do any kind of mapping, it’s a pure reservation mechanism, which relies on the fact that all kernel device … Read more
remove -serial stdio parameter add -nographic parameter and change the kernel parameter terminal = ttyS0 to console=ttyS0. This should do the trick. qemu -nographic -kernel ./bzImage -hda ./image.hda -append root=/dev/sda console=ttyS0 You may want to check the script I use for kernel development: https://github.com/arapov/wrap-qemukvm (it’s not very “production”, but you can find useful qemu cli … Read more
Below is a really basic perl script I wrote. With a bit of tweaking it could be useful. You just need to change the paths I have to the paths of any processes that use Java or C#. You could change the kill commands I’ve used to restart commands also. Of course to avoid typing … Read more
After calling switch_to(), the kernel stack is switched to that of the task named in next. Changing the address space, etc, is handled in eg context_switch(). schedule() cannot be called in atomic context, including from an interrupt (see the check in schedule_debug()). If a reschedule is needed, the TIF_NEED_RESCHED task flag is set, which is … Read more
Fixed this issue by setting the limits for all users in the file : $ cat /etc/security/limits.d/custom.conf * hard nofile 550000 * soft nofile 550000 REBOOT THE SERVER after setting the limits. VERY IMPORTANT: The /etc/security/limits.d/ folder contains user specific limits. In my case hadoop 2 (cloudera) related limits. These user specific limits would override … Read more
The init routines for a module that is initialized by the kernel (when they are statically linked into the kernel) are wrapped in an initcall() macro that indicates when in the startup sequence they should be run. See the include file: include/linux/init.h for a list of the macros and their ordering. The order specified there … Read more
Assuming your kernel was built with the IKCONFIG option, you can use the scripts/extract-ikconfig tool to extract the original .config file. Alternately, you can boot that kernel and find the embedded configuration in /proc/config.gz.
I think you have to do just one command and use the created file as you want to. % make savedefconfig % cp defconfig arch/arm/configs/my_cool_defconfig (Pay attention to the filename template that is used for defconfig) To get all possible targets just run % make help As noted by Adam Miller followed by Jeremy, users … Read more
dtc -O dts sudo apt-get install device-tree-compiler dtc -I dtb -O dts -o a.dts a.dtb gives a well indented textual representation of the device tree a.dtb, which is easy to understand with a text editor. Or dump it to stdout with: dtc -I dtb -O dts -o – a.dtb The source code for dtc is … Read more